Radial-flow turbine of double rotation type



June 7, 1949. R. o. J. MGLLER I RADIAL FLOW TURBINE OF DOUBLE ROTATIONTYPE Filed Dec. 10, 1943 Patented June 7, 1949 RPIM ELQW INE. Qli D UQZE,

RQTATION its-sea Qlev ht illzi l an nsnon Sw den The present inventionrelates to elastic fluid turbines of the radial flow typ having bladesand rotating in opposite directions.

It is. a well-known fact that in this; type of turbillet great. leakagelosses appear between the in dividual blade rings-resultingin areduction of the einciencyi Several proposals have been made in orderto. overcome this diIh-culty. According to one proposal the turbine is'used' as the main part of a combined turbine. also including anauxiliary turbine of the impulse type. By this means aconsiderablyhigher efiioiencyof the turbine aggregate as a whole. may beobtained due to the tact that the impulseturbine when driven by steam.orother' elastic fluid ofhigh pressure and great velocity develops ahighereificiency than a turbine operating on. the reaction p incipl igythe term *impulse turbine is meant a turbine in; which the driving fluidacts as a. positive im-. pellen Amongst other advantages obtained bythis combination of an impulse turbine and a reaction turbine, it is. tobe, noted that the stationary nozzles belonging to the impulse turbineare subjected to less leakaselosse's and; permit a partial go rnin artiaadmission thereby sm losses are obtained as compared with these re-.sulting from the hitherto almost exclusively used throttling orstagegovernin method. The impulse turbine yields a great initialexpansion and a: resulting great drop oi pressureand tempera titr n itsnq a the et turll not b subjected to he ish itial or sure nd he. hinitial mperatu the drivfiuid, as steam. 'The partial admission as usedin connection with'the action turbine requires longer blades resultingin an increased efficiencyr Th v n ages oi. the eaib nat above. reterredto of a aux iary W tee o the impulse tree d a dial 19W i turb of h actype d pend e g the 115.30? an impulse turbine as ge The radial flowturbine itself, h ot undergo any but tethe imraimw win to the met thatthe t am d s har ed trm e. impulse turbine flows from outside inwardlythrough the radial flow turbine. The highest drops of pressure andtemperature of the radial flow turbine will thus take place in thewidest blade rings where the greatest losses appear.

The object of the invention is to provide a combined turbine comprisingan auxiliary impulse turbine and a radial flow main turbine of thereaction type in which combination also the reaction turbine assists inincreasing the efil- 1 and temperature in that alread met .1 v. ose firnew thrauab the blade. as o he radial flow turbine taxin the arge t inmtes Mor over. the radia ex en ion or the me as of the reaction turbinewillbecome o sid r-ably less than that of aturbine having but, a singleor un t ry bladins, and the losses oi the rea tion turbine are reducedawording-hr. The same com"v merit applies also to thelealcagelossesappearingin the labyrinth packings and thershaft packings. All of theabove stated circumstances assist in improving the eflicienoy;

In the accompanying drawing two embodiments of the invention areillustrated.

.Fig. 1 i an axial section of part of a turbine according to oneembodiment and Fig. 2 is a diagrammatic agtial section 9; part ofaturbine according to the other embodiment.

With reference to Fig; 1, the reierence numerals l and 2 designate thetwo turbine shafts a e for po ite otat o listed to he h t are t o ei llysraq dturhine lisqe t and t. T e d sc 1 er resea o e t e bit h nd.@ZF-iifibi Qf ib? @9512! i 23, i 1 15 4 1S? heat d st e y he m dle o themist-t The. urbine than! 2. asse ts a turbine dist 5- were; senting theother, viz. the right handfqigtlfe ne dist 93 t e 222192 1? QR-9?: RYmean 9f: t d umshaped connecting member 6 fastened to the outerperiphery of disc 5, the latter carries an inwardly projecting turbinedisc 1 located in the space between the turbine discs 3 and 4. Theturbine discs 3 and I project rather far beyond the periphery of thedrum 6. At its outer periphery the disc 3 carries a set of impulseblades 8, and at a somewhat smaller diameter the disc I carries acorresponding set of impulse blades 9. It is to be noted that, ofcourse, more than two sets of impulse blades may be provided between theturbine discs 3 and 7.

On their sides facing each other the turbine discs 1 and 4 carry a groupof blades l9 for radial admission of the driving fluid. The oppositesurfaces of the discs 4 and 5 carry similarly another group of blades Hfor radial admission.

Provided in the portion of stationary turbine casing I2 surrounding theblade rings 8 and 9 is a set of nozzles 13, through which the drivingfluid, as for instance steam, is admitted to the outermost ring ofimpulse blades 8, causing said ring to rotate in a definite direction.The driving fluid as discharged from the blade ring 8 impels the bladering 9, causing it to rotate too, though in the opposite direction. Thedriving fluid as discharged from the blades 9 flows inwardly through thepassage l4 formed between the turbine discs 3 and I, as indicated by anarrow, and enters at the inner end of said passage the axial passage l5by which it is conveyed to the blade group 10 through which the fluidpasses from inside outwardly. The fluid as discharged from the bladegroup It at the outer periphery thereof is conveyed by the axial passageinside the cylindrical wall 6 to the outer periphery of blade group I Ithrough which the fluid flows inwardly to be then finally dischargedfrom the turbine through the ports I6, I! formed in the turbine discs 3,4 and 5 and the associated outlet pipes l8, l9. As the outlet ports 16and I! are located at a very small distance from the turbine axis, theleakage losses along the turbine shafts become very small.

At appropriate points, as for instance, axially outside the turbinediscs 3 and 5, labyrinth packings as 20 and 2| may be provided.

If desired, blade rings for radial admission may also be provided in thespaces between the turbine discs 3 and I, as indicated at 22.

The outer portions of the turbine discs 3 and I are formed with ports 23and 24, respectively, through which steam for balancing purposes may beadmitted to the labyrinth packings 20 and 2|, respectively; the axialthrusts acting on the outermost portions of the discs 3, 1 however,balance each other.

In the embodiment above described, the driving fluid passes from outsideinwardly through the blade rings 8 and 9 of the auxiliary impulseturbine. It is to be noted that the reversed direction of flow may beused, though only when the impulse turbine comprises but one blade ring.An embodiment of a corresponding turbine is indicated in Fig. 2. Thedriving fluid flows in the direction indicated by arrows, that is tosay, it is admitted by the stationary inlet 25 to the single blade ring26 of the impulse turbine and is conveyed when discharged therefrom, bythe stationary reversing conduit 27 to the passage between the turbinediscs 3 and I at the inner end of which the fluid alters its directionof flow and enters the blade group I0 to then pass through the turbinein the way already described.

What I claim is:

A turbine unit comprising a double rotation 4 radial flow turbine havingtwo shafts for opposite rotation, two groups of axially spaced radialdiscs alternately arranged with relation to each other so that at leastone disc of each group forms a bafiie between two discs of the othergroup, the discs of one group all being supported at their innerperipheries by one shaft, while only one disc of the other group isdirectly supported at its inner periphery by the other shaft, acylindrical member for connecting an outer point of another disc of saidother group to said directly supported disc, so that the discs and saidcylindrical member form a convolute passage comprising a set of radiallyextending channels between the discs for traverse successively byelastic driving fluid, turbine blades in said channels supportedalternately by one and the other of the respective discs, the blades inthe first radial channel in order of fluid flow which is adapted to betraversed by the driving fluid from outside inwardly being a set ofimpulse turbine blades located at the outer end portion of said firstchannel, the subsequently traversed radial channels each being providedwith a group of reaction turbine blades mounted on the respective discs,the first of said groups of reaction blades being arranged to betraversed by fluid passing outwardly and the last group by fluid passinginwardly, so that the driving fluid is delivered from the blade systemin proximity to the turbine axis, a stationary casing enclosing saiddiscs and blades, labyrinth packings sealing said discs and blades insaid casing, the discs carrying the impulse blades being of a largerdiameter than the remaining discs, the projecting portions of saidlarger discs being exposed to passages leading to the outer periphery ofsaid packings and being formed with ports for allowing fluid that haspassed the impulse blade system to reach the outer ends of the labyrinthpackings for balancing purposes. I

RAGNAR OLOV JACOB MoLLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 849,420 Nussbaumer Apr. 9, 19071,157,727 Rockman Oct. 26, 1915 1,914,752 Moller June 20, 1933 1,944,537Wiberg Jan. 23, 1934 2,218,957 Moller Oct. 22, 1940 FOREIGN PATENTSNumber Country Date 537,917 Germany Nov. 19, 1931 569,206 Germany Jan.30, 1933 700,037 Germany Feb. 4, 1941 703,503 Germany Mar. 11, 1941OTHER REFERENCES Croft, Steam Turbine, Principles and Practice, pub.1923 by McGraw-Hill Book Co., N. Y.

